JP4237564B2 - Method for manufacturing slider pad of transducer cooperating with moving magnetic medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the field of magnetic transducers (heads) for use with moving magnetic media, and more specifically, in a data storage system, a method of manufacturing a pad on a slider surface including an air bearing surface of a transducer facing the moving media. About.
[0002]
[Prior art]
A typical head disk system 10 according to the prior art is shown in FIG. The magnetic transducer 20 is supported by the suspension 13 during operation and floats on the disk 16. A magnetic transducer is usually called a “head” or “slider”, and is composed of an element responsible for writing magnetic transitions (write head 23) and an element responsible for reading magnetic transitions (read head 12). The
[0003]
Electrical signals from the read head 12 and to the write head 23 flow through a conductive path (lead wire) 14 attached to or incorporated in the suspension 13. There are usually two pairs of electrical connection pads (not shown), each pair for a read head 12 and a write head 23, respectively. Wires or lead wires 14 are connected to these pads, creating a route through the suspension 13 to the arm circuit (not shown).
[0004]
The disk 16 is attached to a spindle 18, and the spindle 18 is driven by a spindle motor 24 to rotate the disk 16. The disk 16 includes a substrate 26 and a plurality of thin films 21 formed thereon. The thin film 21 includes a ferromagnetic material, and the write head 23 records magnetic transitions in which information is encoded. Read head 12 reads magnetic transitions as disk 16 rotates under an air-bearing surface (ABS) of head 20.
[0005]
In a typical thin film magnetic transducer manufacturing process, multiple transducers are formed simultaneously from a single wafer. After the basic structure is formed, the wafer is sliced into quadrants or rows, and a pad structure forming process is performed by a lapping process and a lithographic etching technique which is a conventional technique. Finally, the row shape is sliced into individual transducers.
[0006]
As shown in FIG. 8, the ABS of the magnetic transducer 20 is usually formed in the shape of a rail 27 extending from the slider body in the medium direction. This determines the aerodynamics, and the transducer and the disk are either rotated or stationary. It becomes the contact surface when the disc comes into contact. Landing pads 29 or bumps are formed on the rails and other surfaces of the ABS to reduce the adsorption that occurs when the rails 27 come into contact with a stationary disk surface.
[0007]
Although only a few pads 29 are shown in FIG. 8, there can be hundreds of tiny pads on or near the rail. These pads are usually formed by laser spot heating to the rail surface, but photolithography is also used to form a multilayer pad structure. The present invention described below relates to a process for manufacturing a pad using photolithography.
[0008]
The pad is formed by a photolithography technique, and a photoresist pattern having a void in the pad region is formed. Next, a pad material is formed on the entire surface including the photoresist. When the photoresist is removed, the pad material deposited on the photoresist material is removed, leaving a pad in the void portion of the photoresist. The photoresist can usually be removed by applying a liquid solvent and then brushing.
[0009]
[Problems to be solved by the invention]
One problem with conventional photolithographic techniques is that the pad material tends to deposit on the sidewalls of the photoresist surrounding the pad area, resulting in the formation of pad material ridges or fences around the outer edge of the pad. is there. This pad material fence can damage the disk and can break and the debris can damage the disk and other components in the drive.
[0010]
The “Durable Landing Pads for an Air-Bearing Slider” by Han et al. In US Pat. No. 6,236,543 typically used very hard materials with higher stresses. It deals with the delamination problem associated with the pad, which is sometimes accompanied. One solution to this problem is to form pads of tetrahedral amorphous carbon (t-aC), a very hard material, and stress such as Si, SiC, SiO ₂ or Si ₃ N ₄ It has been proposed to relieve stress by sandwiching at least one layer of relaxation material. In order to round the top of the pad, t-aC rotational oblique deposition has been proposed, which makes it possible to form smooth corners.
[0011]
What is needed is a method of manufacturing a durable slider pad that minimizes the fence structure.
[0012]
[Means for Solving the Problems]
A method for manufacturing a transducer having a landing pad without a fence at the edge is described below. The pad shape and its position are determined by voids in the photoresist formed on or near the rail surface using conventional methods. The first layer of the pad structure is preferably filmed as an adhesion layer or seed layer using a vertical beam angle. The next layer is a pad layer, which is preferably deposited at a non-perpendicular (tilted) angle according to the prior art, as determined by pad topography. The final masking layer is formed perpendicular to the pad layer and serves as an anisotropic protective layer in the next ashing step.
[0013]
The vertical film formation process minimizes the deposition of masking layer and seed layer material on the resist void sidewalls. In this way, by forming the masking layer vertically, the fence structure has a much thinner masking layer and seed layer material than the planar structure portion. The thickness of the masking layer on the surface of the pad layer should then be thick enough to protect the pad layer during ashing with oxygen plasma, but the masking material on the fence side wall of the pad layer The thickness must be thin enough so that the fence is not protected during ashing. The masking layer must be a material that will be a protective oxide that prevents subsequent oxygen plasma penetration.
[0014]
After each layer of the pad material is formed, the resist is preferably peeled off by a method including mechanical polishing (for example, cleaning using soda blast or a solvent). After stripping the photoresist material, the structure is ashed with a plasma containing oxygen. Since the masking layer does not protect the fence structure as much as the pad layer, the ashing process removes the pad layer fence structure. Mechanical polishing further ensures the removal of the fence by breaking thin masking pieces on the fence. During the ashing, it is expected that most of the masking layer is structurally discontinuous and changes to an unsupportable oxide. The remaining masking material and oxide material are removed by sputter etching, so that the pad layer is exposed and the fence is not present.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The adhesive and pad layers according to the present invention are formed using conventional techniques, resulting in the deposition of material on the sidewalls that will become the fence when the photoresist is removed as described above. The present invention uses a substantially zero incident angle (in a direction perpendicular to the substrate plane) for forming the masking layer in removing the pad layer fence. When the masking layer is formed by using a direction-dependent means such as ion beam or sputtering by a substrate voltage bias, for example, the film formation speed in a plane perpendicular to the ion beam is a film in a plane parallel to the beam. It becomes considerably larger than the formation speed. This ratio can typically be about 7 to 1. That is, when the film is formed in a substantially vertical direction (0 degree with respect to the vertical plane), the thickness of the masking layer on the side wall of the fence (parallel to the beam) is about the thickness of the pad layer surface (perpendicular to the beam). Only one-seventh.
[0016]
That is, the masking layer is thick enough to prevent oxidation of the underlying pad layer, but sufficient to protect the fence “mountains” against oxygen plasma attack. If it is not a thickness, it means that there is a “usable range”. The exact limit of masking layer thickness for proper operation will vary depending on parameters such as film forming device characteristics, materials used and oxygen plasma pressure. The thickness range of the masking layer is expected to be on the order of 5-50 Angstroms. If the masking layer and seed layer are filmed according to the present invention, the fence will be discontinuous. Mechanical polishing as seen from resist stripping further weakens the mask layer on the sidewalls, but not the pad surface. This is because the mask on the pad surface is thicker and, to a lesser extent, the fact that the fence shape is prone to large lateral deflections due to mechanical forces. Oxygen plasma irradiation (ashing) and mechanical erosion make the sidewall material into pieces of sponge-like hollow oxide (eg, SiOx) that cannot stand on its own.
[0017]
On the other hand, if the ion beam deposition or sputtering beam flow is set to 45 degrees or any other non-directional film formation method is used, the pad surface and the fence surface have the same masking layer thickness. And will exhibit the same masking effect. If the thickness of the masking material is the same on the sidewalls and flat surfaces, ashing will not have the anisotropic effect of preferentially ashing the fence material without removing the pad itself. Eventually the usable range will be much narrower or zero.
[0018]
An embodiment of the present invention will be described with reference to FIG. Here, although not shown, the transducer is incorporated in a slider having a pad structure. FIG. 1 shows a portion of a transducer 20 that includes a plurality of magnetic transducers formed according to the prior art. Voids between the photoresist films 41 are also formed by conventional techniques. The photoresist film 41 is formed on the layer 43 made of a material constituting the slider body.
[0019]
The adhesive layer 44 is formed on the photoresist and the void. The adhesive layer 44 used with the carbonaceous pad material may be any carbide forming material such as titanium or silicon, but silicon is more suitable. These materials oxidize during ashing. Further, the adhesive layer 44 is preferably deposited in the vertical direction for the same reason as in the masking layer 46.
[0020]
The adhesive layer 44 is relatively thin as compared with the next functional layer, and it is sufficient if it has a thickness that is effective for adhesion, and a thickness of about 10 angstroms or more is sufficient. As with the other layers, the thickness of the adhesive layer is determined experimentally in consideration of the design requirements of the storage system in which the slider is used. One design requirement is the total thickness of the pad including the adhesive layer. This is because it limits the distance between the magnetic sensor incorporated in the slider and the magnetic recording medium.
[0021]
The pad layer 45 is formed much thicker than the thickness of the adhesive layer 44. In general, the thickness of the pad layer is determined based on the principles of the prior art, for example, to optimize adsorption and wear resistance. Current designs use pad layers with a thickness of about 150-600 Angstroms. A suitable material for the pad is diamond-like-carbon (DLC). The carbon may be a hydrogen compound or a nitrogen compound, or may contain other functional additives. Other durable materials are also used within the scope of the present invention so long as the material evaporates sufficiently (i.e., forms a gas phase reductate) during ashing in an oxygen plasma or other plasma. be able to.
[0022]
Masking material 47 is shown in the film formation process of FIG. The masking material 47 is preferably a material that protects by forming a dense, adherent oxide when exposed to oxygen. Silicon is preferred. The arrow indicates that film formation is suppressed so that the film formation angle theta (θ) is small, ie, substantially perpendicular to the surface (perpendicular film formation).
[0023]
Vertical film formation is used to minimize the deposition of the film forming material on the sidewalls. Vertical film formation can be achieved by conventional techniques such as ion beam evaporation and bias sputtering. FIG. 2 shows the state of the ABS after the masking layer 46 is formed.
[0024]
FIG. 3 shows the structure after the photoresist material 41 has been removed. The photoresist material 41 is preferably stripped by a technique that weakens or reduces the fence by mechanical polishing, for example, soda blasting or cleaning with a solvent.
[0025]
FIG. 4 is an enlarged view of the region indicated by E1 in FIG. 3 in order to more clearly describe the microstructure / micro-layout of the edges of the masking layer 46 and the pad layer 45. In FIG. The raised structural portions 46F and 45F are undesirable fences as described above. FIG. 5 shows the result after ashing this structural portion in oxygen plasma. Oxygen turns the carbon of the thin fence structure into ash and destroys the entire fence with mechanical erosion during resist removal, resulting in a more rounded structure suitable for the edges of the pad layer 45.
[0026]
The masking layer that protects the pad is relatively thick and creates a protective oxide, thus serving as a continuous covering and protection for the pad layer 45. Although the embodiment described here includes stripping the resist before the ashing step, it is expected that similar results will be achieved even if ashing is performed before stripping the resist. FIG. 6 shows that the masking layer 46 is removed by sputter etching, resulting in a pad layer 45 with rounded edges. Depending on the situation, an additional overcoat layer may be formed on the pad and slider surfaces.
[0027]
The layers, structures and materials of the head embodying the present invention other than the materials, thickness values, etc. specified above shall be according to the prior art and manufactured according to the prior art.
[0028]
The composition shown here has been described without considering the small amount of impurities that are unavoidably present in practical examples, but this is well known to those skilled in the art.
[0029]
Although the present invention has been described by way of specific examples as examples of the present invention, the invention described herein is not limited to these specific examples, and various modifications and changes within the scope of the present invention by those skilled in the art. It is clear that a correction will be made.
[Brief description of the drawings]
FIG. 1 is an explanatory view of forming a vertical masking layer on a slider pad structure according to an embodiment of the present invention.
FIG. 2 is an illustration of a pad structure after a vertical film formation process according to an embodiment of the present invention.
FIG. 3 illustrates the manufacturing state of the pad structure after the photoresist is stripped during the process according to one embodiment of the present invention.
4 is an enlarged view of a region indicated as E1 in FIG. 3;
5 is an enlarged view of the region labeled E1 in FIG. 3 after oxygen plasma ashing and mechanical polishing.
6 is an enlarged view of the region labeled E1 of FIG. 5 after sputter etching according to the present invention.
FIG. 7 is an explanatory diagram of a prior art showing a relationship between a head and related parts in a disk drive.
FIG. 8 is an explanatory diagram of a landing pad structure according to the prior art relating to an air bearing surface of a slider.
[Explanation of symbols]
20 ... Transducer, 41 ... Photoresist film, 43 ... Slider body layer,
44 ... Adhesive layer or seed layer, 45 ... Pad layer, 46 ... Masking layer,
47 ... Masking material, 44F, 45F, 46F ... Fence (raised structure).

Claims (22)

Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming an adhesion layer or a seed layer with anisotropy so as to be thinner on the side wall than on the bottom surface of the void; and
Forming a fence on the side wall of the void on the slider body, and forming a pad layer having one surface;
Forming a masking layer to be thinner and anisotropic on the sidewall fence than on the surface of the pad layer;
Stripping the photoresist material to remove the pad layer and masking layer other than the voids;
Removing the fence from the pad layer by ashing;
Removing the masking layer and the adhesive or seed layer on the sidewall;
A method of manufacturing a slider pad of a magnetic transducer, comprising: The process according to claim 1, wherein the adhesive layer or seed layer is a carbide-forming material. The process according to claim 1, wherein the adhesive layer or the seed layer is silicon. Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming a fence on the side wall of the void on the slider body, and forming a pad layer having one surface;
Forming a masking layer to be thinner and anisotropic on the sidewall fence than on the surface of the pad layer;
Peeling the photoresist material by mechanical polishing to remove the pad layer and masking layer other than the voids; and
Removing the fence from the pad layer by ashing;
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising : Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming a fence on the side wall of the void on the slider body, and forming a pad layer having one surface;
Forming a masking layer to be thinner and anisotropic on the sidewall fence than on the surface of the pad layer;
Stripping the photoresist material with soda blast to remove the pad layer and masking layer other than the voids;
Removing the fence from the pad layer by ashing;
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising : Forming a slider body including a magnetic transducer;
Forming a void having a side wall in the photoresist material to define the position and shape of the pads on the slider body,
Forming a fence on the side wall of the void on the slider body, and forming a pad layer having one surface;
Forming a masking layer to be thinner and anisotropic on the sidewall fence than on the surface of the pad layer;
Stripping the photoresist material by cleaning with a solvent to remove the pad layer and masking layer other than the voids; and
Removing the fence from the pad layer by ashing;
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising : Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming a fence on the side wall of the void on the slider body, and forming a pad layer having one surface;
Forming a masking layer to be thinner and anisotropic on the sidewall fence than on the surface of the pad layer;
Stripping the photoresist material to remove the pad layer and masking layer other than the voids;
Removing the fence from the pad layer by ashing by exposure to a plasma containing oxygen;
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising : Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming a fence on the side wall of the void on the slider body, and forming a diamond-like carbon pad layer having one surface;
Forming a masking layer to be thinner and anisotropic on the sidewall fence than on the surface of the pad layer;
Stripping the photoresist material to remove the pad layer and masking layer other than the voids;
Removing the fence from the pad layer by ashing;
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising : Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming a fence on the side wall of the void on the slider body, and forming a pad layer having one surface;
Forming a masking layer of protective oxide forming material to be thinner and more anisotropic on the sidewall fence than on the surface of the pad layer;
Stripping the photoresist material to remove the pad layer and masking layer other than the voids;
Removing the fence from the pad layer by ashing;
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising : Forming a slider body including a magnetic transducer;
Forming a photoresist material film on the surface of the slider body;
Forming voids in the photoresist material to determine the position and shape of the pads;
Forming an adhesive layer or seed layer vertically over the photoresist and void;
Forming a pad layer on the adhesion layer or seed layer with a first material that evaporates when exposed to oxygen plasma;
Vertically forming a masking layer with a second material that forms a protective oxide when exposed to oxygen plasma;
Stripping the photoresist material to remove the adhesive or seed layer, pad layer and masking layer other than the voids;
Removing the fence material from the pad layer by ashing with a plasma comprising oxygen;
Removing the masking layer and the adhesion layer or seed layer in the void;
A method of manufacturing a slider pad of a magnetic transducer, comprising : The manufacturing method according to claim 10, wherein the adhesive layer or the seed layer is silicon . The manufacturing method according to claim 10, wherein the pad layer is diamond-like carbon . The manufacturing method according to claim 10, wherein the masking layer is silicon . The adhesive layer or seed layer Ri silicon der, the pad layer is a diamond-like carbon method according to claim 10, wherein the masking layer is silicon. The method according to claim 10, wherein the step of removing the masking layer further includes sputter etching . The method of claim 10, wherein the step of stripping the photoresist material further comprises mechanically polishing the photoresist material . The method according to claim 10, wherein the step of removing the photoresist material further includes cleaning using a soda blast or a solvent . Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming a carbide forming material adhesive layer or seed layer so that it is thinner and more anisotropic on the sidewalls than on the bottom surface of the void;
Forming a fence on the side wall of the void, and forming a pad layer having one surface on the slider body;
Forming an anisotropic masking layer that is thinner on the sidewall fence than on the pad layer surface; and
Removing the fence from the pad layer by ashing;
A step of removing the Fotore resist material to remove said pad layer and the masking layer is in other than the void portion,
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising : The manufacturing method according to claim 18, wherein the adhesive layer or the seed layer is silicon . Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming a fence on the side wall of the void, and forming a pad layer having one surface on the slider body;
Forming an anisotropic masking layer that is thinner on the sidewall fence than on the pad layer surface; and
Removing the fence from the pad layer by ashing;
Peeling the photoresist material by mechanical polishing to remove the pad layer and masking layer other than the voids; and
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising : Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming a fence on the side wall of the void, and forming a pad layer having one surface on the slider body;
Forming an anisotropic masking layer that is thinner on the sidewall fence than on the pad layer surface; and
Removing the fence from the pad layer by ashing by exposure to a plasma containing oxygen ;
Stripping the photoresist material to remove the pad layer and masking layer other than the voids;
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising: Forming a slider body including a magnetic transducer;
Forming voids having sidewalls in the photoresist material to determine the position and shape of the pads on the slider body;
Forming a fence on the side wall of the void, and forming a pad layer having one surface on the slider body;
Forming an anisotropic masking layer of oxide-forming material that is thinner on the sidewall fence than on the surface of the pad layer; and
Removing the fence from the pad layer by ashing;
Stripping the photoresist material to remove the pad layer and masking layer other than the voids;
Removing the masking layer;
A method of manufacturing a slider pad of a magnetic transducer, comprising :

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